LIQUID EVAPORATOR

• US 20070107879A1
• Filed: 10/02/2006
• Published: 05/17/2007
• Est. Priority Date: 11/15/2005
• Status: Active Grant

• Current Assignee: Dragerwerk AG & Company KGaA (FPS Vermögensverwaltung GmbH)
• Original Assignee: Drager Medical AG & Co KG (Dragerwerk AG)
• Inventors: KOCH, Jochim, RADOMSKI, Klaus, WRUCK, Norbert
• Granted Patent: US 7,992,554 B2
• Time in Patent Office: Days
• US Class Current: 165/104.260
• CPC Class Codes: A61M 16/109 the humidifying liquid or the beneficial agent
• CPC Class Codes: A61M 16/142 with semi-permeable walls separating the liquid from the respiratory gas
• CPC Class Codes: A61M 16/147 the respiratory gas not passing through the liquid container
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/18 Vaporising devices for anaesthetic preparations
• CPC Class Codes: A61M 2205/3372 Temperature compensation
• CPC Class Codes: Y10S 159/15 Special material
• CPC Class Codes: Y10S 159/27 Micropores
• CPC Class Codes: Y10S 159/28 Porous member
• CPC Class Codes: Y10S 159/906 Wick

Abstract

A liquid evaporator includes a liquid reservoir (3) with a liquid to be evaporated, a heater (9) and an evaporator tube (12). The evaporator tube (12) has a first porous element (1) having a first porosity and with an area in contact with the liquid in the liquid reservoir (3) and a second porous element (2) with a second porosity and with an area present on an evaporator side (50) used to dispense the evaporated liquid, and an area outside the liquid reservoir heated by the heater (9) which is not directly in connection with the liquid. The first porous element and the second porous element are in contact in contact areas with the first porous element forming a wick delivering liquid from the reservoir to the contact area.

Claims

1. A liquid evaporator comprising:

a liquid reservoir with a liquid to be evaporated;

an evaporator tube;

a heater for heating the evaporator tube, the evaporator tube having adjacent areas consisting of materials of different porosities, including one or more areas with one or more porous sintered glass or porous sintered ceramic elements, which said areas are in connection with the liquid in the liquid reservoir and are present on one front side of the liquid evaporator wherein the other front side is used to dispense the evaporated liquid, and an area of the evaporator tube outside the liquid reservoir, which said area is heated by means of the heater provided with a porous sintered metal or said porous sintered ceramic, which is not directly in connection with the liquid with at least two different cross section distributions of the materials having different porosities present in the longitudinal direction of the liquid evaporator, and the areas in the liquid evaporator are adjacently in connection by means of three-dimensionally shaped contact areas.

2. A liquid evaporator in accordance with claim 1, wherein the area or areas of the liquid evaporator that is/are in connection with the liquid is/are equipped with a gas-tight jacket or is/are inserted into the evaporator tube such that the liquid cannot escape to the outside against the direction of dispensing from the evaporator tube when a respiration pressure is present on the front side to dispense the evaporated liquid.

3. A liquid evaporator in accordance with claim 1, wherein the mean pore size of the sintered metal or sintered ceramic which is not directly in connection with the liquid is greater than about 40 μ

m and the mean pore size of the sintered glass or sintered ceramic element which is in connection with the liquid is 10 μ

m to 40 μ

m in case of the evaporation of water and 1 μ

m to 40 μ

m in case of the evaporation of anesthetic.

4. A liquid evaporator in accordance with claim 1, wherein the sintered metal consists of a stainless steel or an alloy containing copper or a chrome-nickel alloy.

5. A liquid evaporator in accordance with claim 1, wherein the liquid evaporator is provided with a first temperature sensor for regulating the heating capacity of said heater downstream of the section heated by means of the heater.

6. A liquid evaporator in accordance with claim 5, wherein the liquid evaporator is provided with a second temperature sensor upstream of the section heated with the heater for regulating the heating capacity of the heater so that overheating of the section upstream of the heated section is prevented.

7. A liquid evaporator in accordance with claim 1, wherein the front side for dispensing the evaporated liquid is connected to an evaporator chamber in the breathing gas flow of a patient, especially as part of an anesthesia apparatus or a respirator.

8. A liquid evaporator in accordance with claim 1, wherein the liquid is one of an anesthetic, water, a solution or a solution containing a drug.

9. A liquid evaporator in accordance with claim 1, wherein the sintered ceramic consists of Al₂O₃.

10. A liquid evaporator in accordance with claim 1, wherein the three-dimensionally shaped contact area is designed in the form of a cone, a sphere or a rotation paraboloid, especially with a convex or concave shape.

11. A liquid evaporator in accordance with claim 1, wherein the area or areas of the liquid evaporator that is/are in connection with the liquid in the liquid reservoir is/are inserted into the evaporator tube such that a gap formed between the evaporator tube and the at least one sintered glass or sintered ceramic element is at most 10 times the mean pore size of the element, so that the liquid cannot escape to the outside against the direction of dispensing from the evaporator tube and also no leakage of gas can thus occur when a respiration pressure is present on the front side for dispensing the evaporated liquid.

12. A liquid evaporator comprising:

a liquid reservoir with a liquid to be evaporated;

a heater;

an evaporator tube which is heated by said heater, said evaporator tube having adjacent areas comprising materials having different porosities, wherein one or more of said areas including one or more porous sintered glass or porous sintered ceramic elements with areas in connection with the liquid in the liquid reservoir being present on one front side of the liquid evaporator and the other front side being used to dispense the evaporated liquid, and including an area of the evaporator tube outside the liquid reservoir heated by means of the heater and equipped with a porous sintered metal or said porous sintered ceramic which is not directly in connection with the liquids wherein at least two different cross section distributions of the materials having different porosities are present in the longitudinal direction of the liquid evaporator, and the area or areas of the liquid evaporator that are in connection with the liquid are equipped with a gas-tight jacket or are inserted into the evaporator tube such that the liquid cannot escape from the evaporator tube to the outside against the direction of dispensing when a respiration pressure is present on the front side for dispensing the evaporated liquid.

13. A liquid evaporator in accordance with claim 12, wherein the areas in the liquid evaporator are adjacently in connection by means of thee-dimensionally shaped contact areas.

14. A liquid evaporator in accordance with claim 12, wherein the mean pore size of the sintered metal or sintered ceramic which is not directly in connection with the liquid is greater than about 40 μ

m and the mean pore size of the sintered glass or sintered ceramic element which is in connection with the liquid is 10 μ

m to 40 μ

m in case of the evaporation of water and 1 μ

m to 40 μ

m in case of the evaporation of anesthetic.

15. A liquid evaporator in accordance with claim 12, wherein the sintered metal comprises a stainless steel or an alloy containing copper or a chrome-nickel alloy.

16. A liquid evaporator in accordance with claim 12, wherein the liquid evaporator is provided with a first temperature sensor for regulating the heating capacity of said heater downstream of the section heated by means of the heater.

17. A liquid evaporator in accordance with claim 16, wherein the liquid evaporator is provided with a second temperature sensor upstream of the section heated with the heater for regulating the heating capacity of the heater so that overheating of the section upstream of the heated section is prevented.

18. A liquid evaporator in accordance with claim 12, wherein the front side for dispensing the evaporated liquid is connected to an evaporator chamber in the breathing gas flow of a patient, especially as part of an anesthesia apparatus or a respirator.

19. A liquid evaporator in accordance with claim 12, wherein the liquid is one of an anesthetic, water, a solution or a solution containing a drug.

20. A liquid evaporator in accordance with claim 12, wherein the sintered ceramic consists of Al₂O₃.

21. A liquid evaporator in accordance with claim 12, wherein the three-dimensionally shaped contact area is designed in the form of a cone, a sphere or a rotation paraboloid, especially with a convex or concave shape.

22. A liquid evaporator in accordance with claim 12, wherein the area or areas of the liquid evaporator that is/are in connection with the liquid in the liquid reservoir is/are inserted into the evaporator tube such that a gap formed between the evaporator tube and the at least one sintered glass or sintered ceramic element is at most 10 times the mean pore size of the element, so that the liquid cannot escape to the outside against the direction of dispensing from the evaporator tube and also no leakage of gas can thus occur when a respiration pressure is present on the front side for dispensing the evaporated liquid.

25. A liquid evaporator in accordance with claim 12, wherein the first porous element and second porous element are adjacently in connection by means of three-dimensionally shaped contact areas.

23. A liquid evaporator comprising:

a liquid reservoir with a liquid to be evaporated;

a heater;

an evaporator tube with first porous element having a first porosity and with an area in contact with the liquid in the liquid reservoir and a second porous element having a second porosity and with an area present on an evaporator side used to dispense the evaporated liquid, said evaporator tube having an area heated by the heater which is not directly in connection with the liquid, said first porous element and said second porous element being in contact with each other in a contact area with said first porous element forming a wick delivering liquid from the reservoir to said contact area.

24. A liquid evaporator in accordance with claim 23, wherein the area or areas of the liquid evaporator that is/are in connection with the liquid includes a sealed wick connection including a gas-tight jacket or insertion of the evaporator tube into the liquid such that the liquid cannot escape to the outside against the direction of dispensing from the evaporator tube when a respiration pressure is present on the evaporator side to dispense the evaporated liquid.